This application relates to the art of temperature sensing and, more particularly, to temperature sensing of a flowing liquid. The invention is particularly applicable for use in sensing the temperature of water flowing to a clothes washing machine and will be described with specific reference thereto. However, it will be appreciated that the invention has broader aspects and can be used for sensing the temperature of other flowing liquids in other environments.
The temperature of the hot and cold water supplied to a washing machine varies greatly. For example, in many geographical areas, the cold water supply often has a much lower temperature during winter than during summer. The temperature of the hot water supply varies greatly from one household to another depending on the setting of the hot water heater and the distance that the washing machine is located from the water heater. Also, there is often a difference in the flow rates of the hot and cold water. For these reasons, simply opening both the hot and cold water valves one hundred percent to supply warm water results in an actual warm water temperature that has extremely wide variations. Water that is too hot may damage certain clothes and water that is too cold may not clean effectively. In addition, the unnecessary use of excessive hot water is energy inefficient and environmentally unfriendly. Therefore, it would be desirable to have an arrangement for accurately sensing the temperature of warm water being supplied to a washing machine in order to cycle or modulate at least the hot water valve and thereby maintain a relatively constant warm water temperature.